/**
 * Copyright (c) 2021 OceanBase
 * OceanBase CE is licensed under Mulan PubL v2.
 * You can use this software according to the terms and conditions of the Mulan PubL v2.
 * You may obtain a copy of Mulan PubL v2 at:
 *          http://license.coscl.org.cn/MulanPubL-2.0
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 * See the Mulan PubL v2 for more details.
 */

#ifndef OCEANBASE_SQL_OB_EXPR_COLLATION_H_
#define OCEANBASE_SQL_OB_EXPR_COLLATION_H_

#include "sql/engine/expr/ob_expr_operator.h"
namespace oceanbase {
namespace sql {
/// Returns the character set of the string argument.
class ObExprCharset : public ObStringExprOperator {
  public:
  // ObExprCharset();
  explicit ObExprCharset(common::ObIAllocator& alloc);
  virtual ~ObExprCharset();

  virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;
  virtual int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const;
  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const;

  private:
  // types and constants
  private:
  // disallow copy
  DISALLOW_COPY_AND_ASSIGN(ObExprCharset);
  // function members
  private:
  // data members
};

/// Returns the collation of the string argument.
class ObExprCollation : public ObStringExprOperator {
  public:
  // ObExprCollation();
  explicit ObExprCollation(common::ObIAllocator& alloc);
  virtual ~ObExprCollation();

  virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;
  virtual int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const;
  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const;

  private:
  // types and constants
  private:
  // disallow copy
  DISALLOW_COPY_AND_ASSIGN(ObExprCollation);
  // function members
  private:
  // data members
};

/// Returns the collation coercibility value of the string argument.
/// @see ObCollationLevel
class ObExprCoercibility : public ObExprOperator {
  public:
  // ObExprCoercibility();
  explicit ObExprCoercibility(common::ObIAllocator& alloc);
  virtual ~ObExprCoercibility();

  virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;
  virtual int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const;
  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const;

  private:
  // types and constants
  private:
  // disallow copy
  DISALLOW_COPY_AND_ASSIGN(ObExprCoercibility);
  // function members
  private:
  // data members
};

/// change collation of the input argument
/// used to implement COLLATE clause, e.g. C1 collate utf8_general_ci, 'abc' collate utf8_bin
/// format: SET_COLLATION(expr, utf8_general_ci)
class ObExprSetCollation : public ObExprOperator {
  public:
  // ObExprSetCollation();
  explicit ObExprSetCollation(common::ObIAllocator& alloc);
  virtual ~ObExprSetCollation();

  virtual int calc_result_type2(
      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
  virtual int calc_result2(
      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const;

  private:
  // types and constants
  private:
  // disallow copy
  DISALLOW_COPY_AND_ASSIGN(ObExprSetCollation);
  // function members
  private:
  // data members
};

/// Returns the meta used for comparison
/// @note for debug purpose
class ObExprCmpMeta : public ObStringExprOperator {
  public:
  // ObExprCmpMeta();
  explicit ObExprCmpMeta(common::ObIAllocator& alloc);
  virtual ~ObExprCmpMeta();

  virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;
  virtual int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const;
  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const;

  private:
  // types and constants
  private:
  // disallow copy
  DISALLOW_COPY_AND_ASSIGN(ObExprCmpMeta);
  // function members
  private:
  // data members
};

}  // end namespace sql
}  // end namespace oceanbase

#endif  // OCEANBASE_SQL_OB_EXPR_COLLATION_H_
